Method for preparing coated binder units

Abstract

A method and apparatus for preparing a plurality of coated binder units are disclosed. A coated binder is divided into a plurality of coated binder units by applying a pair of dividing elements to the coated binder and applying a welding element.

What is claimed is: 
     
       1. A method for preparing a plurality of coated binder units wherein each of the coated binder units comprises a core of a binder coated with a layer of coating material, which method comprises the steps of:
 (a) providing a coated binder which comprises a core of a binder coated with a layer of coating material; and 
 (b) dividing the coated binder into the plurality of coated binder units by 
 (i) applying a pair of dividing elements to the coated binder, 
 (ii) moving the pair of dividing elements from a closed configuration to an open configuration, thereby removing the binder from a region of the coated binder such that two layers of coating material are adjacent to one another; and 
 (iii) applying a heated welding element to the two layers of coating material that are adjacent to one another in the region of the coated binder wherein the binder has been removed by the pair of dividing elements, wherein the heated welding element has a temperature sufficient to weld and cut the coating material and effectively seal the coated binder units such that the layer of coating material is substantially continuous. 
 
     
     
       2. A method according to  claim 1 , wherein the binder is a bituminous binder or is a synthetic binder comprising a resin, an oil and optionally a polymer. 
     
     
       3. A method according to  claim 2 , wherein the binder is a bituminous binder. 
     
     
       4. A method according to  claim 1 , wherein the coating material is a polymer or a blend comprising at least 50 wt % polymer. 
     
     
       5. A method according to  claim 1 , wherein the dividing elements are heated to a temperature of from 25 to 140° C. 
     
     
       6. A method according to  claim 1 , wherein the welding element is heated to a temperature of from 100 to 300° C. 
     
     
       7. A method according to  claim 1 , wherein step (b) further comprises the step of:
 (iv) removing the welding element and the pair of dividing elements from the coated binder, and returning the pair of dividing elements to the closed configuration. 
 
     
     
       8. A method according to  claim 4 , wherein the coating material is polyethylene or a blend comprising at least 50 wt % polyethylene. 
     
     
       9. A method according to  claim 5 , wherein the dividing elements are heated to a temperature of from 40 to 60° C. 
     
     
       10. A method according to  claim 6 , wherein the welding element is heated to a temperature of from 120 to 165° C.